A new diterpene alkaloid, which has been called coryphine, has been isolated from the plant Aconitum coreanum (Levl.) Rapaics. This is the first diterpene alkaloid containing, like atisine, an oxazolidine ring with a C14-C20 bridge and a 2,3,3a,6,7,7a-hexahydro-N-methylindolin-6-one fragment. The structure of coryphine was established by x-ray structural investigations of its perchlorate. © 1991 Plenum Publishing Corporation.